I posted this at the Yahoo reeltoreel group, but no answers so far, so I
thought I'd try here.

Just picked up my first reel to reel- an Akai GX-266D.
It's in very good cosmetic condition, but the transport doesn't work,
at least not properly. While the capstan motor(?)appears to be working
fine, pressing the play or fast-forward/reverse buttons does nothing.

I can get the motors to turn the reels by manually engaging the
solenoid(s), so I know the motors work. Probing the relay coil I see
that there is no signal to the relays when pressing any of the
buttons. Actually, I measure 24VDC on one of the relay coils, but when
pressing transport buttons neither side goes to ground as I would expect.

I found a dead transistor (TR4: D361 90V NPN), and replacing it
yielded a temporary semi-functional response. IOW, one of the play
LEDs was lit upon power-up, and pressing the play button actually
resulted in reel rotation! Unfortunately, it stopped working whenI
pressed the stop button, and I couldn't get it to work again until I
touched up the solder joints on the replaced transistor. After that it
temporarily worked again for a few button presses, then quit.

Any advice (or a schematic!) would be greatly appreciated.

Thanks,
Sam Lloyd